Driving mechanism



H. C. ZIEBER DRIVING MECHANISM Dec. 10, 1968 Filed March 9, 1967 2 Sheets-Sheet 1 INVENTOR.

m. I 2 CV w! m H JIE. Z

Dec. 10, 1968 H. c. ZIEBER 3,415,131

DRIVING MECHANISM Filed March 9, 1967 2 Sheets-Sheet 2 JIE. 5

INVENTOR. HAZOLD C. ZIE'BEZ BY W7 W7 HIS flTTOENEVS United States Patent 3,415,131 DRIVING MECHANISM Harold C. Zieber, 218 Fike Ave., Orrville, Ohio 44667 Filed Mar. 9, 1967, Ser. No. 621,862 Claims. (Cl. 7431) ABSTRACT OF THE DISCLOSURE An apparatus for reciprocably driving a load support carriage along a trackway by a unidirectional rotary motor mounted on the carriage. The motor directly drives a gear which intermittently engages along the top and the bottom of a row of pins parallel to the trackway. The gear is guided around the row of pins from top to bottom, and vice versa, at the end of each carriage stroke in either direction. By moving the pins into operative positions or into inoperative positions, the effective stroke of the carriage or the position of the carriage with respect to the trackway is changed.

carriage itself. In part, this invention consitutes an improvement of the device shown in US. Letters Patent No. 2,953,876, issued to H. C. Zieber et al., on Sept. 20, 1960, and which discloses a more complex mechanism for reciprocably driving the carriage.

An object of this invention is to provide a novel device for converting rotary motion into linear motion. More specifically, an object of this invention is to provide a sprocket or gear pinion engaging a series of aligned, equally spaced, movably mounted pins functioning as ratchet teeth, the number of which may be changed by withdrawing the pins out of reach of the sprocket or projecting pins into the reach of the sprocket, the sprocket or gear pinion following a curved path centered about the last projecting tooth or pin so as to transfer it to the opposite side of the gear teeth or pins, and the pinion causing a relative to and fro movement between the pinion and the support for the ratchet teeth. The pinion may be driven from any suitable motor such as an electric motor, air motor, hydraulic motor, internal combustion engine or any other suitable source of continuous rotary power.

Other objects and advantages reside in the construction of parts, the combination thereof, the method of manufacture and the mode of operation, as will become more apparent from the following description.

In the drawings, FIGURE 1 discloses a partial front elevational view of a sand blasting machine for engraving tombstones, plaques, and so forth, with a sprocket wheel or gear pinion illustrated as beginning travel in one direction along a series of pins or ratchet teeth.

FIGURE 2 is an enlarged, fragmentary cross sectional view taken substantially on the section line 22 of FIG- URE l but illustrating parts after the sprocket wheel or gear pinion has advanced to a position near the opposite end of the ratchet teeth or pins.

FIGURE 3 is an enlarged fragmentary elevational view Patented Dec. 10, 1968 taken in the direction of the arrows 3-3 of FIGURE 2.

FIGURE 4 is a fragmentary view of a portion of the support for the gear teeth or pins, some of which are withdrawn from operative position, as viewed in the direction of the arrows 4-4 of FIGURE 3.

FIGURE 5 is a fragmentary cross sectional view of a portion of the machine taken along line 5-5 of FIGURE 1, and showing a work piece therein.

The device disclosed herein incorporates a curtain assembly driven up and down by one type of drive mechanism substantially identical to the curtain drive mechanism shown in the aforementioned Zieber et a1. Patent No. 2,953,876, which drive mechanism will be first described. A second drive mechanism for driving the sand blast jet in a direction at right angles to the movement of the curtain assembly, which differs from the drive mechanism shown in said patent, incorporates the novelty disposed herein.

(I) The curtain assembly and the first drive mechanism This invention is described in connection with a booth or enclosure 10 (FIGURE 1) adapted to receive Work 11 (FIGURE 5) to be acted upon by a blast of comminuted abrasive material 12 which is carried by air or other fluid under pressure and which is discharged by a jet 14 against the exposed surface 18 of the work 11. The work 11 is covered by a stencil 16, made of rubber or the like, which is adhesively secured to the work 11 in a manner so it may later be removed, as is well known in the art. The desired configurations are cut in the stencil 16, as indicated at 17, to expose the work surface 18. The abrasive material may be sand of the desired degree of comminution propelled by a blast of fluid, such as air under pressure, discharged through the nozzle 20 of the jet 14 which is connected by a flexible conduit 22 (FIG- URE 1) to an automatic air and sand mixer (not shown) of well known construction. Merely as an illustration, the jet 14 may extend sixteen inches into the enclosure 10 and the end of the nozzle 20 may be approximately nine inches from the work 11.

In reference to FIGURE 1, the enclosure 10 has an access opening indicated by the dotted rectangle 25 and is maintained at a slightly subatrnospheric pressure by means of a suction fan or blower diagrammatically indicated at 26, which blower discharges into a suitable sand separator (not shown) normally located outside the building housing the booth or enclosure 10.

A frame having channel-shaped sides 28 and 29 and a channel=shaped top member 30 is provided with means for attachment to the booth or enclosure 10 adjacent the access opening 25. Such attachment means may take the form of brackets 32 connected to the sides 28 and 29 of the frame and to the sides of the enclosure 10 by screw bolts 34. Suitable spacers 36 may be included to compensate for dimensional variations between the frame and the enclosure 10.

The frame (28, 29 and 30) serves as a support for a curtain assembly adapted to be placed in front of the access opening 25, the curtain assembly having a sealing surface cooperating with the access opening 25 in sufiicient sealing relationship with the enclosure 10 to prevent any substantial outward escape of air and abrasive material past such sealing surface. As illustrated, such curtain assembly may include an upper flexible curtain 40, a lower flexible curtain 41 and an intermediate panel construction generally designated 42. Such curtain assembly (40, 41 and 42) is movable transversely of the access opening 25, preferably in a vertical direction. As illustrated, the upper curtain 40 may wind and unwind upon a roller 44. Upward tension is exerted upon the curtain 40 by a pair of counter balance weights 46 attached to a pair of cables 47 fixed to and wrapped around a pair 3 of pulleys 48 fixedly secured to the roller 44. The roller 44 may be supported on bearing plates 49 extending upwardly from the sides 28 and 29 of the frame.

The intermediate panel construction 42 may be raised and lowered by a reversible motor 50 mounted on a bracket 51 at the upper end of the frame side member 29. The reversible motor 50 drives a gear reducer 52 which, in turn, drives a pulley and belt transmission 53, reversibly to rotate a shaft 54 supported by a plurality of bearing members 55 on top of the upper frame member 30. Cables 56 are attached to an upper metal angle member 58 of the panel construction 42, so that the panel construction 42 is raised and lowered by the reversing rotation of the motor 50.

The panel construction 42 is one rigid structure between the upper metal angle 58 and a lower, horizontal metal channel member 60, these members being united by vertical side metal members 61. The upper edge of the flexible curtain 41 is secured to the lower metal member 60. The curtain 41 is made of a heavy fiexible material so that it can hang, slide and pleat at 62 near the lower part of the booth 10. The construction of the curtain assembly (40, 41 and 42) is such that its position is governed by the position of the panel construction 42 which, in turn, is determined by the reversible rotation, or non-rotation, of the motor 50. The weight of the panel construction 42 is such that it dominates the position of the entire curtain structure (40, 41 and 42) as it hangs on the cables 56 which wind and unwind on the shaft 54. The upper curtain 40 is maintained under tension at the position determined by the position of th panel construction 42 and by the action of the weights 46. The lower curtain 41 hangs from the panel construction 42 and is maintained under tension by its own weight as it pleats upon itself at 62.

A horizontal slot 63 is provided in a rubber sheet 64 of the panel construction 42. The jet 14 passes through the slot 63 and can be moved horizontally therealong since the slot 63 temporarily spreads as shown in FIG- URE 5. The jet 14 carries a plate 66 which bears tightly on the sheet 64 to prevent any accidental outward leakage or escape of sand around the jet 14. The jet 14 is supported for lateral movement on the panel construction 42 by a carriage 68 provided with a first set of wheels 70 which ride in a trackway formed by the lower channel 60. An upper channel 72, securely held in parallel relation to lower channel 60 in the panel construction 42, guides and confines a second set of wheels 70 on the carriage 68. The carriage 68 and the jet 14 are moved back and forth along the slot 63 by a mechanism to be described. The panel construction 42 also includes a metal sheet or plate 74 which has a horizontal clamping construction 76 to receive the lower edge of a plurality of window panes 78, which panes 78 are held at their upper edges by a clamping construction 80 depending from the angle member 58.

The structure described thus far is substantially the same as the structure disclosed in the above Patent No. 2,953,876.

(II) The second drive mechanism In accordance with this invention, the carriage 68 and the jet 14 moving therewith are driven to and fro by a rotary motor, such as an electric, air, hydraulic, or internal combustion motor 90 or any other type of rotary motor. The motor 90 is mounted in a split sleeve 92 which sleeve has a pair of oppositely disposed, radially projecting pivot pins 94, only one of which is shown. These pins 94 project through holes in the outer ends of a pair of arms 96 fixedly attached to the carriage 68. The elongated armature shaft 100 of the motor 90 has keyed to the outer end thereof .a sprocket wheel or gear pinion 102 meshing with a plurality of pins 104 which serve as rack gear teeth and which are aligned in a row parallel to the trackway formed by the lower channel 60. The

pins 104 are mounted for movement from operative to inoperative positions in a support channel 106 having its ends fixedly attached to the vertical frame members 61 attached to the transverse members 58 and 60 so as to move up and down with the curtains 40 and 41. As best seen in FIGURE 2, the flanges 106A and 106B of the channel 106 are provided with pairs of equally spaced apertures, each pair of apertures supporting a pin 104. Each pin 104 is encircled by a compression spring 105 seated between the flange 106A and a retaining ring 108 seated in an annular groove extending around each pin 104. The springs 105 bias the pins 104 outwardly from the channel flange 106B into an operative position wherein they may be reached by the pinion 102. A retaining ring 109 on each pin 104 limits such outward movement, which is toward the right as viewed in FIGURE 2. To prevent the sand from escaping around the pins 104 and possibly interfering with the movement thereof, a closed end channel member (FIGURE 5) may be mounted in covering relation to the pins 104 on the inside face of the plate 74.

With reference to FIGURES 2 and 4, a pair of modified C-clamps 110 provided with flanges engaging the rear side of the channel flange 106B and the rear side of a rib 112 welded on top of the channel 106 are mounted for slidable movement along the channel 106. Each 'C-clamp 110 supports a clamping bar 113 which may be moved toward and away from the exposed face of the channel flange 106B by a manually operable screw 107. As apparent, when the clamping bars 113 are moved into a position abutting the channel 106B, the spaced pins 104 engaged thereby are placed against the bias of their associated springs in a retracted, inoperative position out of the reach of the pinion 102. In FIGURE 2 it may be observed that two pins 104 are illustrated, one pin 104 being projected outwardly by its associated spring 105 and the other pin 104 retracted by the clamping bar 113.

At the end of each stroke of the carriage 68, its direction of movement is reversed as illustrated in FIGURE 3. Assuming a clockwise direction of rotation of the motor shaft 100 as viewed in FIGURE 3, the pinion 102 rotates about the last pin 104 in the series of operative pins located between the clamping bars 113. Thus, as indicated by the arrows in FIGURE 3, the pinion 102 is about to pivot about the last pin 104. The pinion 102 is guided during this movement by a guide plate 114 attached to the adjacent C-clamp 110, the guide plate 114 having an arcuate recessed surface 115 engaging and guiding a loosely mounted bearing collar 116 on the motor shaft 100. Both C-clamps carry guide plates 114 so mounted that their recessed surfaces are mutually confronting and are each concentric with the immediately adjacent end pin of the portion of the row of pins 104 operatively positioned in the reach of the pinion 102.

Before the pinion 102 has pivoted about the end pin 104 illustrated in FIGURE 3, it will, of course, be supported by the row of pins 104. After the pinion 102 has pivoted from above the pins 104 to below the pins 104, it is maintained engaged therewith by a plate 118 having an oblong slot 120 which limits the swinging or pivotal movement of the motor 90 and the pinion 102 about the pivot pins 94. The plate 118, as illustrated, may conveniently be supported by the arms 96. Assumin the clockwise rotation of the motor shaft 100 continues, the pinion 102 will ride along the bottom of the pins 104 until the pinion 102 approaches the C-clamp 110 to the left as viewed in FIGURE 1, whereupon the pinion 102 is pivoted to the top of the pins 104. Lateral movement of the motor shaft 100 relative to the carriage 68 is not provided for and is positively prevented by the design of the slot 120. It is thus apparent that, as the pinion 102 travels back and forth along the pins 104, the carriage 68 travels therewith. It is also apparent that the motor 90 may be a simple unidirectional motor.

The length of each stroke of the carriage 68 is determined by the number of pins 104 in operative position.

that is the position in which they are within the reach of and engageable by the pinion 102, and forming the portion of the row of pins 104 between the two C-clamps 110. As already made apparent, the length of the stroke of the carriage 68 as well as the start and finish point for each stroke of the carriage 68 can be changed by changing the relative spacing of the C-clamps 110 and the position thereof with respect to the cabinet 10. The length of the strokes is adjusted to be consistent with the desired travel of the jet 14 so as to cover the needed work area that is to be sand blasted. If, for example, the decorated or engraved area of the work 11 is 24 inches in length, the length of each stroke would then be slightly more than 24 inches so that the jet stream would be directed against a solid portion of the stencil 16 while the pinion 102 travels around the end pins of the portion of the row of pins 104 in operative position between the spaced C- clamps 110. On the other hand, in the event the engraved face of the stone is 36 inches, the length of each stroke should be slightly more than 36 inches.

The travel of the curtain structure including the intermediate panel construction 42 may be controlled by a switch 122 mounted on the frame member 29 engaged by adjustable stops 124. Upon each engagement of the switch 122 by one of the stops 124, the direction of the rotation of the motor 50 is reversed. The relative speeds of the two motors 50 and 90 is such that the motor 90 rapidly drives the carriage 68 laterally back and forth in a direction perpendicular to the direction of movement of the intermediate panel construction 42 many times between each reversal of the motor 50 so that sand will be uniformly blasted against the exposed area of the work 11.

Although the preferred embodiment of the invention has been described, it will be understood that various changes may be made within the scope of the appended claims.

Having thus described my invention, I claim:

1. A driving device for converting rotary motion into linear motion, said device including a support, a carriage mounted for movement on said support, a motor mounted on said carriage, a pinion driven by said motor, a row of pins mounted on said support and each of said pins being movable from an operative position to be engaged by said pinion to an inoperative position out of the reach of said pinion, means projecting said pins into said operative position, and means releasably holding spaced ones of said pins in said inoperative position whereby said pinion can engage only those of said pins between said pins in said inoperative position.

2. The device of claim 1 wherein said means projecting said pins into said operative position includes a plurality of springs, each spring biasing one of said pins into operative position, and wherein said means releasably holding spaced ones of said pins in said inoperative position includes a clamp member overlying said pin in inoperative position.

3. The device of claim 1 wherein a trackway is formed on said support, said carriage being movable along said trackway, and wherein said row of pins is parallel to said trackway.

4. The device of claim 1 wherein said motor drives said pinion in one direction and said pinion is guided around the end ones of said pins between said pins in inoperative position by a pair of guide members having confronting arcuate recesses concentric with said end pins whereupon said carriage reciprocates along a path the length of which is determined by the number of pins located between said pins in said inoperative position.

5. The device of claim 4 wherein a trackway is formed on said support, said carriage being movable along said trackway, and wherein said row of pins is parallel to said trackway.

6. The device of claim 4 wherein said means projecting said pins into said operative position includes a plurality of springs, each spring biasing one of said pins into operative position, and wherein said means releasably holding spaced ones of said pins in said inoperative position includes a clamp member overlying said pins in inoperative position.

7. The device of claim 6 wherein said pair of guide members are mounted on said clamp members, there being one of said guide members on each one of said clamp members.

8. In an apparatus for moving in two mutually perpendicular directions a tool or other device mounted in a carriage of the type wherein said carriage is movably supported in a trackway formed on a first support which is reciprocably driven on a second support for movement in a direction perpendicular to said trackway, the improvement comprising a row of pins mounted on said first support in parallel relation to said trackway, a motor mounted on said carriage and driving a pinion engageable iwth said pins, and releasable means positioning selected ones of said pins out of the reach of said pinion whereby only a portion of said row of pins is positioned to be engaged by said pinion.

9. The apparatus of claim 8 wherein said motor is pivotally mounted on said carriage for movement in a direction perpendicular to said row of pins and wherein means are provided limiting movement of said pinion in both a direction parallel to and perpendicular to said pins such that said pinion will be engaged with at least one pin at all times.

10. The apparatus of claim 9 wherein said last mentioned means includes a pair of guide members having confronting arcuate surfaces each of said surfaces being concentric with an end pin of said portion of said row of pins.

References Cited UNITED STATES PATENTS 2,208,590 7/1940 Leonard et al. 7431 2,857,697 10/1958 Schutt et al 7489.17 2,953,876 9/1960 Zieber et al 51-8 FREDERICK L. MATTESON, JR., Primary Examiner. E. G. FAVORS, Assistant Examiner.

US. Cl. X.R. 51-8 

